题解 | SQL类别高难度试卷得分的截断平均值
SQL类别高难度试卷得分的截断平均值
https://www.nowcoder.com/practice/a690f76a718242fd80757115d305be45
select tag,difficulty,
round(avg(score),1) as clip_avg_score
from examination_info ei
join exam_record er
on ei.exam_id = er.exam_id
where tag='SQL'
and difficulty ='hard'
and score not in (
select max(score) as extreme from exam_record
union all
select min(score) as extreme from exam_record )
group by tag,difficulty
难点在于通过子查询去除最高分和最低分
